Rotary kiln



July 29, 1924. J. s. FASTING ROTARY KILN Filed Sept-8, 1923 IN l/E N TOR .re s. rnsrrne, or VALBY, amen cornnnnenn, nun-Mann, nssrenon ror. L. SMIDTH a cm, or n roan, n. r, A conronn'rron or new JERSEY.

Application filed September To all" whom it may conocmr I Be it known that I, JoHAN S. FAs'mNo,

a subject of the Kin of Denmark, residing in Monrads Alle 9, alby, near Copenhagen, Denmark, have invented certain new and useful Improvements in Rotary Kilns, of which the following is a specification, referdrical or tubular sections of sheet metal, of

uniform diameter, butt-joined to form a continuous tube by butt-straps of sheet metal which cover the butt-joints between the sections and are riveted to adjoining sections. The kiln thus produced, being of uniform diameterfrom end to end, isnot of such shape as to yield the best results in the burning of the'cement raw materials. The velocity at which the materials being burned travel through a cylinder of uniformdiameter from end to end will obviously be substantially the same at every part'of the cylinder, the inclination at the bottom part of the cylinder, on which the materials aresupported, being the same at all points. Under ideal conditions of operation, however,

, the materials under treatment should move at a greater velocit through certain zones of the kiln than t rou h others. Thus, particularly in cement urning kilns, the materials should pass through the drying zone, that is, the upper zone or the zone nearest the end at which the materials are i fed into the kiln, more rapidly than through the burning zone, nearer the discharge end of the kiln, in'which the sinterin of the materials is'cariied on. It is also esirable, in the operation of such kilns, thatthe -ve- .locity of the hot products-of combustion should increase'jtoward the end of the kiln at which they escape and at which the raw materials are fed in. It has been proposed heretofore to meet the requirement for the relative reduction of the speed of travel of the materials being treated through the burning zone b making the corresponding portion of the 'ln of relatively larger diameter, but the construction proposed has n been such as to introduce practical difiiculties in construction as well as in operation. By the construction which forms the sub- 8, 1923. Serial'No. 661,620.

ject of the present invention it is possible both to meet the technical requirements with regard to the speed of travel of the material and of the hot products of-combustion' by riveting or other suitable means. The

invention will be more fullyexplained hereinafter with reference to the accompanying drawing in which it is illustrated and in whichv Figure 1 is a view in elevation of a kiln constructed in accordance with the inventioi, with some of the appurtenant devices, an

Figure 2 is a partial view of the same in longitudinalsection and on a larger scale.

That portion of the kiln, usually at about the middle, which should have the greatest diameter and in which the materials being burned. should have or commence their slowest travel, is formed of a cylindrical or tubular section a of maximum diameter. The next adjacent section a, at one side or at each side as the case may be, is of a diameter less than that of the section a by substantially the thickness of the metal em loyed so that it can be fitted into the end of-the section a for a distance suflicient. to make a ti ht joint and to permit it to be secured 51 means, such as rivets, indicated at a.- In like manner each successive section, as a a, etc.,- is smaller in diameter than the one erein by any suitable- As-will be observed by reference to the drawings, the inclinationof the bottom of the kiln, on which the materials are supported during their progress through the kiln, is greatest in the upper or feedin portion of the kiln in which the materia s are subjected to the drying action, while the inclination of the bottom rtion of the kiln toward the lower or disc arge end is least. Thus the materials being treated will travel with a maximum velocity through the drying zone and with a minimum velocity through the loweror burning zone. Furthermore, it will be observed that the say-- ing of weight of metal employed in the new construction is considerable, not only by reason of the successively smaller diameters of the sections employed, but also by reason of the fact-that the overla of two adjacent sections may be only a ut half of the width oi the butt-strap heretofore employed. Furthermore, the labor employed in the construction of the new kiln is less than in the construction of the old form of kiln because the overlap of two adjacent sections can be secured by a single line of rivets whereas two lines of rivets are required for each butt-strap heretofore employed.

I claim as my invention;

A rotary kiln formed of a series of tubular sections of successively reduced diameters with the section of maximum diameter between the ends of the kiln and the successive sections toward each end of the kiln of successively reduced diameters and secured within the next adjacent section at one side.

This specification August, A. D. 1923.

J OHAN S. FASTING'.

signed this 11th day of 

